Solar system
Moons
Dozens of worlds orbit the planets of our solar system. Some are frozen and quiet; others are hot, active, and among the most promising places to search for life beyond Earth.
Europa
An icy moon with a subsurface ocean that may harbor conditions suitable for life.
Considered one of the most promising places to search for life beyond Earth.
Moons by host planet
Moons of Earth
The Moon
Earth's only natural satellite, the Moon stabilizes our planet's tilt and drives ocean tides.
Diameter: 3,474.8 km
Moons of Mars
Phobos
The larger and closer of Mars's two moons, orbiting less than 6,000 km above the surface.
Diameter: 22.4 km
Deimos
The smaller and more distant of Mars's two moons.
Diameter: 12.4 km
Moons of Jupiter
Io
The most volcanically active body in our solar system.
Diameter: 3,643.2 km
Europa
An icy moon with a subsurface ocean that may harbor conditions suitable for life.
Diameter: 3,121.6 km
Ganymede
The largest moon in the solar system, larger than the planet Mercury.
Diameter: 5,268 km
Callisto
A heavily cratered icy world and one of the most cratered bodies in the solar system.
Diameter: 4,820.6 km
Moons of Saturn
Titan
Saturn's largest moon, with a thick nitrogen atmosphere and lakes of liquid methane.
Diameter: 5,149.5 km
Enceladus
A small icy moon that erupts water plumes from a subsurface ocean.
Diameter: 504.2 km
Mimas
A small moon of Saturn best known for the enormous Herschel crater on its surface.
Diameter: 396 km
Moons of Neptune
Triton
Neptune's largest moon and the only large moon that orbits its planet in the opposite direction.
Diameter: 2,706.8 km